Interfacially Al-doped ZnO nanowires: greatly enhanced near band edge emission through suppressed electron-phonon coupling and confined optical field

Yiming Wu; Yanmeng Dai; Shenlong Jiang; Chao Ma; Yue Lin; Dongxue Du; Yukun Wu; Huaiyi Ding; Qun Zhang; Nan Pan; Xiaoping Wang

doi:10.1039/c7cp00973a

Interfacially Al-doped ZnO nanowires: greatly enhanced near band edge emission through suppressed electron-phonon coupling and confined optical field

Phys Chem Chem Phys. 2017 Apr 5;19(14):9537-9544. doi: 10.1039/c7cp00973a.

Authors

Yiming Wu¹, Yanmeng Dai¹, Shenlong Jiang¹, Chao Ma¹, Yue Lin¹, Dongxue Du¹, Yukun Wu¹, Huaiyi Ding¹, Qun Zhang², Nan Pan³, Xiaoping Wang³

Affiliations

¹ Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China. [email protected] [email protected].
² Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China. [email protected] [email protected] and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
³ Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China. [email protected] [email protected] and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.

PMID: 28345696
DOI: 10.1039/c7cp00973a

Abstract

Aluminium (Al)-doped zinc oxide (ZnO) nanowires (NWs) with a unique core-shell structure and a Δ-doping profile at the interface were successfully grown using a combination of chemical vapor deposition re-growth and few-layer Al_xO_y atomic layer deposition. Unlike the conventional heavy doping which degrades the near-band-edge (NBE) luminescence and increases the electron-phonon coupling (EPC), it was found that there was an over 20-fold enhanced NBE emission and a notably-weakened EPC in this type of interfacially Al-doped ZnO NWs. Further experiments revealed a greatly suppressed nonradiative decay process and a much enhanced radiative recombination rate. By comparing the finite-difference time-domain simulation with the experimental results from intentionally designed different NWs, this enhanced radiative decay rate was attributed to the Purcell effect induced by the confined and intensified optical field within the interfacial layer. The ability to manipulate the confinement, transport and relaxation dynamics of ZnO excitons can be naturally guaranteed with this unique interfacial Δ-doping strategy, which is certainly desirable for the applications using ZnO-based nano-photonic and nano-optoelectronic devices.